Embodiments of the present invention relate to uses of melanin in water. One such use includes methods for reducing and regulating the acidification of water. In particular, one embodiment of the present invention relates to a method for reducing the acidification of water, particularly seawater, by contacting the water with at least one melanin material in order to catalyze a reaction between water, carbon dioxide (CO2) and/or bicarbonate in order to produce glucose, sucrose, or other organic compounds which increases the pH of the water and reduces the acidification of the water. In another aspect, the invention allows for maintaining the pH of the water at a desired level based on the surrounding conditions simply by keeping the melanin material in contact with the water or removing it therefrom. In another aspect, an embodiment of the present invention relates to the synthesis of amino acids and complex organic molecules arising from CO2 or glucose, sucrose or the other organic compounds.
The rise of atmospheric CO2, generated primarily from human fossil fuel combustion, has induced a significant decrease in the pH of ocean water, commonly referred to as ocean or seawater acidification. More particularly, ocean acidification occurs because atmospheric CO2 gas is absorbed by and dissolved in seawater and causes a series of chemical reactions that ultimately decreases pH in ocean water. Specifically, once atmospheric CO2 is dissolved in water, ocean carbonate chemistry is governed by the following series of chemical reactions:CO2 (atmos)↔CO2 (aq)+H2O↔H2CO3↔H++HCO3−↔2H++CO32−
Air-sea gas interchange equilibrates surface water CO2 to atmospheric levels of CO2. Aqueous CO2 gas reacts with water to form carbonic acid (H2CO3), which can then be dissociated by losing hydrogen ions to form bicarbonate (HCO3−) and carbonate ions (CO32−). As a result, with increasing atmospheric CO2, aqueous CO2, bicarbonate, and hydrogen ion concentrations tend to increase, while pH and carbonate ion concentration tend to decrease. Ocean uptake of CO2 may be responsible for alleviating nearly a third of anthropogenic CO2 (i.e., CO2 generated by human activity) which is released to the atmosphere. In other words, rising levels of atmospheric CO2 are tempered by ocean uptake of CO2, a phenomenon which is well documented in field data. To understand the changing chemistry of the oceans and the process of ocean acidification on marine ecosystems, researchers have been studying how CO2 emissions affect the ocean ecosystem for more than three decades, and continue to monitor ocean acidification in the world's oceans.
Ocean acidification has been found to alter seawater chemical speciation and bio-geo-chemical cycles of many elements and compounds. Photosynthetic algae and sea grasses may actually benefit from higher CO2 conditions in the ocean. However, multiple studies have revealed concerns that establish ocean acidification as a threat to marine wildlife. Acidic environments have been shown to have a negative effect on some calcifying species, including oysters, clams, sea urchins, shallow water corals, deep sea corals, and calcareous plankton. One well-known effect is the lowering of calcium carbonate saturation states, which impacts a variety of shell-forming marine organisms, ranging from plankton to benthic mollusks, echinoderms, and corals. Many calcifying species exhibit reduced calcification and growth rates in laboratory experiments under high-CO2 conditions.
Since the beginning of the industrial revolution, the pH of the ocean water surface has fallen by 0.1 pH units due to ocean acidification, representing an approximately 30% increase in acidity of seawater. Future predictions indicate that the oceans will continue to absorb CO2 at accelerated rates and become even more acidic, unless measures are taken to curb CO2 emissions in the atmosphere.
Thus far, the primary ocean acidification management and mitigation actions proposed have focused on reducing anthropogenic CO2 emissions to stabilize air and ocean CO2 concentrations, and maximizing marine wildlife resilience and adaptation to elevated CO2 concentrations using conventional marine management practices, such as pollution and overfishing reduction. However, stabilization of atmospheric CO2 below harmful levels cannot currently be achieved. Also, conventional, passive management practices have not been effective against the impacts of rising CO2 levels. Some alternative physical, biological, chemical, and hybrid conservation methods have also been proposed, but evaluation of the potential effectiveness, cost, safety, and scale of application of such methods has yet to be seriously undertaken.
Further, a variety of schemes have been proposed wherein seawater CO2 acidity could be neutralized through the addition of a base carbonate or silicate minerals and derivatives to the seawater. However, while such chemical methods are commonly used in saltwater aquaria to maintain coral and shellfish health, the potential safety and cost effectiveness of such approaches in addressing local to global ocean acidification have yet to be fully researched.
Accordingly, it would be desirable to provide a process and system for reducing and regulating the pH of seawater to curb ocean acidification and the proven negative impacts thereof.
It would also be desirable to generate organic compounds, such as amino acids and lipids, from the glucose or CO2. As well known to those of ordinary skill in the art, living creatures require, for proper nutrition, a variety of organic compounds, including amino acids, lipids, and others which can be obtained from plants and meat. Conventionally, to obtain such edible molecules, it is necessary to sow and harvest plants or obtain these edible organic compounds from farm animals, which require large harvests, large animal farms, massive use of insecticides to protect crops, fertilizers, herbicides, etc., and large amounts of water
Accordingly, it would be desirable to provide a process and system for generating organic compounds, such as amino acids, lipids and the like, from the glucose or CO2 associated with the reduction and regulation of the pH of seawater.